Introducción a la modelización computacional desde primeros principios y al uso de técnicas experimentales para la caracterización de materiales para aplicaciones en la Industria fotovoltaica

Abstract

Tin sulfide (SnS) is an abundant mineral on earth which has aroused great interest at present as it is a semiconductor chalcogenide with indirect band gap, which has high conductivity and high absorption coefficient. These characteristics make it a material with a wide variety of applications for the photovoltaic industry. In the present work the analysis of the band structure and the calculation of effective masses of the SnS with symmetry (Aem2) 39 for a system of 8 atoms is developed. The calculation was carried out from the first principles in the framework of the density functional theory (DFT), whose formalism is implemented in the Abinit software, using the augmented wave projector (PAW) method, which besides generating good approximations, it is of low computational cost, what allows to study systems conformed by great amount of electrons. Effective mass analysis was performed using the density functional perturbation theory (DFPT), which allowed to study the extreme bands together with the mobility of the carriers in a more precise way. Subsequently, the calculation was proposed for two systems: i) distortion of the SnS network parameter from experimental data made up of 64 atoms and ii) system with a tin vacancy in the structure of the SnS; which require an unfolding of the electronic band structure.